Robert l



(No Model.) v

- -R. L. WALKER.

DAMPER.

No. 293,543. Patented Feb. 12, l884.

IF JEIIIZUY.

UNITED STATES PATENT 0FFI'CE..

ROBERT L. WALKER, OF BOSTON, MASSACHUSETTS,- AssIeNoE To THE WALKER SMOKELESS EUENAOE COMPANY, OF sAME PLACE.

DIAMPER- SPECIFICATION forming part of Letters Patent No. 293,543, dated February 12, 1884.

' Application filed May 23, 1883. (So model.)

To aZZ whom, it may concern.-

Be .it known that I, .ROBERT L. WALKE of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Dampers, of which the following is a specification.

My invention relates to improvements in dampers used to close the outlets of furnaces, more especially of steam-boiler furnaces, in which two separate fires are placed-one at each end of the boilerand by means of dampers the smoke and gases generated in one fire are made to pass over the other fire. My object is to keep the damper from leaking around the edges, when it is in place, even when it may become warped by the heat,

My invention consists in providing the damper with a beveled flange on one side and a concavity on the other side for holdinga refractory sand, and providing the lower damperseat with a concavity for holding a refractory sand. and the upper damper-seat with a beveled flange similar to that on the damper, so that these beveled flanges will penetate this sand to a greater or less depth,aocording to the bends orwarps, and thereby prevent any leakage of gases between the damper and its seats.

In the accompanying drawings, which illustrate a steamboiler with two fires and my improved-damper, Figure 1 is a side elevation, partly in section. Fig. 2 is a longitudinal section, and Fig. 3 is a crosssection through the damper and its seat.

The boiler Ais provided with furnacesB B one at each end-provided with out-lets b b.

These fines E E must be coveredby a damper when the outlet of its furnace is uncovered.

Heretofore the dampers have been made flat, and have rested on flat seats around the outlets and flues; and it has been found that the intense heat warps the dampers more or less, so that they do not fit close to their seats, but allow the smoke and gases from the fresh fuel in the covered furnace to escape unconsumed between them and their seats. With my improved dampers a joint sufficiently tight to prevent any injurious leakageis simply and effectually provided. On the lower side of the dampers, I make abeveled flange or projection, d d, and on the upper side a trough or groove, cl (P. A similar trough is formed around each of the outlets b b, and a similar flange around the flues E E. The troughs are filled to the required depth with a refractory sand, or the like, into which the projections on the lower side of the dampers and the lower side of the flues enter, when the damper is in position to cover these outlets or lines. The sand forms a perfect packing to prevent the escape of smoke or gas between the dampers and their seats. The smoke and gases are therefore compelled to pass over the fire in the uncovered furnace, which, by proper firing, is kept incandescent, and are consumed, thereby preventing smoke and economizing fuel.

I claim as my invention- In a damper for covering openings above and below it, a pointed projection on one side and a trough on'the other side, adapted to entera trough in the lower seat and to receive a pointed projection on the upper seat, substantially as and for the purposes set forth.

ROBERT L. VALKER. 

